<template>
  <view>
    <!-- 使用自定义的搜索组件 -->
    <my-search @click="gotoSearch"></my-search>
    <view class="scroll-view-container">
      <!-- 左侧的滑动区域 -->
      <scroll-view scroll-y="true" class="left-scroll-view " :style="{height: wh + 'px'}">
        <block v-for="(item,i) in cateList" :key="i">
          <view :class="['left-scroll-view-item',i===active ? 'active' : '']" @click="activeChanged(i)">{{item.cat_name}}</view>
        </block>
      </scroll-view>
      <!-- 右侧的滑动区域 -->
      <scroll-view scroll-y="true" class="right-scroll-view" :style="{height: wh + 'px'}" :scroll-top="scrollTop">
        <view class="cate-lv2" v-for="(item2,i2) in catrLevel2" :key="i2">
          <!-- 二级分类的标题 -->
          <view class="cate-lv2-title">-------- {{item2.cat_name}}-------- </view>
          <!-- 当前二级分类下的三级分类列表 -->
          <view class="cate-lv3-list">
            <!-- 三级分类的item项 -->
            <view class="cate-lv3-item" v-for="(item3,i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
              <!-- 三级分类的图片 -->
              <image :src="item3.cat_icon" mode=""></image>
              <!-- 三级分类的标题 -->
              <text>{{item3.cat_name}}</text>
            </view>
            
          </view>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
  export default {
    data() {
      return {
        //当前设备可用高度
        wh: 0,
        cateList: [],
        active:0,
        //二级分类列表
        catrLevel2:[],
        scrollTop:0
      };
    },
    onLoad() {
      //获取当前手机的信息并且将它的长度取出赋给滑动区域
      const sysInfo = uni.getSystemInfoSync()
      this.wh = sysInfo.windowHeight -50
      this.getCateList()
    },
    methods: {
      async getCateList() {
        const {
          data: res
        } = await uni.$http.get('/api/public/v1/categories')
        if (res.meta.status !== 200) return uni.$showMsg()
        this.cateList = res.message
        //为二级分类赋值
        this.catrLevel2 = res.message[0].children
      },
      //改变avtive的值使其动态切换
      activeChanged(i){
        this.active = i
        //重新为二级分类赋值
        this.catrLevel2 = this.cateList[i].children
        //让右侧回归到顶部
        this.scrollTop = this.scrollTop === 0 ? 1 : 0
        
      },
      //跳转到商品列表页面
      gotoGoodsList(item){
        uni.navigateTo({
          url:'/subpkg/goods_list/goods_list?cid=' + item.cat_id
        })
      },
      //搜索框功能
      gotoSearch(){
       uni.navigateTo({
         url:'/subpkg/search/search'
       })
      
      }
    }
  }
</script>

<style lang="scss">
  .scroll-view-container {
    display: flex;

    .left-scroll-view {
      width: 120px;

      .left-scroll-view-item {
        background-color: #f7f7f7;
        line-height: 60px;
        text-align: center;
        font-size: 12px;

        &.active {
          background-color: #ffffff;
          position: relative;

          &::before {
            content: '';
            display: block;
            width: 3px;
            height: 30px;
            background-color: #c00000;
            position: absolute;
            top: 50%;
            left: 0;
            transform: translateY(-50%);
          }
        }
      }
    }
    
    .cate-lv2-title{
      font-size: 12px;
      font-weight: 700;
      text-align: center;
      padding: 15px 0;
    }
    .cate-lv3-list{
      display: flex;
      flex-wrap: wrap;
      
      
      .cate-lv3-item{
        width: 33.3%;
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        margin-bottom: 10px;
        image{
          width:  60px;
          height: 60px;
          border-radius: 2px;
        }
        text{
          font-size: 12px;
        }
      }
    }
  }
</style>